Chemical reactions — IGCSE Chemistry (0971) questions by topic
Chemical reactions questions test rate and redox reasoning: reading a graph of carbon dioxide volume produced at two different temperatures from excess calcium carbonate and acid, judging statements about a catalyst speeding up hydrogen peroxide decomposition, comparing two experiments' gas-volume-against-time graphs, and identifying which equations show a given species acting as a reducing agent. Identify, state, complete, explain and deduce want precise reasoning drawn directly from graphs and equations.
14 questions from 2025 papers sit on this page, worth from 1 to 19 marks. Because rate-graph questions are marked on reading specific features such as gradient and plateau point correctly, submitting an answer for instant marking checks whether a graph has been interpreted for the right feature, such as which curve reaches its maximum volume faster, rather than a superficially similar but wrong reading.
May–June 2025, Paper 11
The equation for the decomposition of hydrogen peroxide is shown. 2H2O2 → 2H2O + O2 The reaction is exothermic. When a small amount of a catalyst is added, the oxygen is produced…
Answer this question and get it marked →The equation for the reaction between copper(II) oxide and carbon is shown. 2CuO + C → 2Cu + CO2 Which statement about this reaction is correct? A CuO is reduced. B CO2 is…
Answer this question and get it marked →May–June 2025, Paper 12
Which process involves a chemical change? A dissolving copper(II) sulfate B distilling ethanol C freezing water D neutralising copper(II) oxide
Answer this question and get it marked →The total volume of gas produced in two different experiments is measured against time. A graph of the results of the two experiments is shown. The graph plots total volume of gas…
Answer this question and get it marked →The equation for the reaction of sulfur dioxide with oxygen is shown. 2SO2 + O2 <= 2SO3 What is meant by the symbol <= ? A redox reaction B reversible reaction C displacement…
Answer this question and get it marked →Which reactions are redox reactions? 1 the incomplete combustion of propane 2 the rusting of iron 3 the reaction of aqueous chloride ions with acidified aqueous silver nitrate 4…
Answer this question and get it marked →May–June 2025, Paper 21
The graph shows the results of adding excess calcium carbonate to hydrochloric acid at 50 C and at 30 C. Only the temperature is changed. The graph plots total volume of carbon…
Answer this question and get it marked →Industrially, ammonia is made by the Haber process. The equation is shown. N2(g) + 3H2(g) <= 2NH3(g) deltaH = -92 kJ/mol The conditions used are 450 C and 200 atm. Which…
Answer this question and get it marked →May–June 2025, Paper 22
Which statement describes the effect of adding a catalyst to a chemical reaction? A The activation energy, Ea, of the reaction is increased. B The enthalpy change, ΔH, of the…
Answer this question and get it marked →Which equations show the underlined species acting as a reducing agent? (The underlined species is shown in brackets.) 1 [Fe2O3] + 3CO - 2Fe + 3CO2 2 [Fe] + CuSO4 - FeSO4 + Cu 3…
Answer this question and get it marked →May–June 2025, Paper 32
Select two processes that show a chemical change. Tick two boxes. boiling water burning methane dissolving salt mixing ink and water rusting of iron
Answer this question and get it marked →May–June 2025, Paper 41
Methanol, CH3OH, is manufactured by the reaction between hydrogen and carbon monoxide. An equilibrium mixture is produced. 2H2(g) + CO(g) ⇌ CH3OH(g) State what happens to the…
Answer this question and get it marked →May–June 2025, Paper 51
Read all of the instructions carefully before starting the experiments. You are going to do five experiments. Experiment 1 - Use the 50 cm3 measuring cylinder to pour 30 cm3 of…
Answer this question and get it marked →May–June 2025, Paper 61
A student investigates how the rate of reaction of magnesium ribbon with dilute acid changes as the concentration of the acid is changed. The student uses five solutions of the…
Answer this question and get it marked →Other IGCSE Chemistry topics
- Organic chemistry (31)
- The Periodic Table (29)
- Metals (23)
- Experimental techniques and chemical analysis (19)
- Acids, bases and salts (14)
- Chemical bonding (11)
- Stoichiometry (11)
- Chemistry of the environment (10)
- States of matter (9)
- Electrochemistry (9)
- Atoms, elements and compounds (8)
- Chemical energetics (8)